<style>
  div > div {
    display: inline-block;
    width: 150px;
    height: 150px;
  }
  #topWide {
    border: 5px solid black;
    border-radius: 0px 0px 50px 50px;
    border-top: 50px solid red;
  }
  #rightWide {
    border: 5px solid black;
    border-radius: 50px 0px 0px 50px;
    border-right: 50px solid red;
  }
  #bottomWide {
    border: 5px solid black;
    border-radius: 50px 50px 0px 0px;
    border-bottom: 50px solid red;
  }
  #leftWide {
    border: 5px solid black;
    border-radius: 0px 50px 50px 0px;
    border-left: 50px solid red;
  }
</style>
<div>
  <div id="topWide"></div>
  <div id="bottomWide"></div>
</div>
<div>
  <div id="rightWide"></div>
  <div id="leftWide"></div>
</div>
